This invention relates to dispensing closures for dispensing liquid products from containers, and to dispensers comprising such a closure mounted on or comprised in a product container. The proposals relate particularly but not exclusively to dispensing closures for squeeze dispensers, in which the container is resiliently squeezable to force product out through an outlet path defined through the closure, and subsequently recovers drawing compensation air back into the container. The invention is particularly concerned with valved closures, in which the closure includes a valve device which opens the outflow path for dispensing and closes it when dispensing pressure is relieved. A valve action offers various advantages, such as protecting product in the container against contamination and giving a clean cut-off of dispensed flow when squeezing is relaxed.
Slit silicone valves are widely used for this purpose: an inwardly-convex silicone rubber dome with crossed through-slits is mounted in the outlet opening. Under sufficient dispensing pressure it inverts, i.e. flips to bulge outwardly, and the slits open up for flow. When pressure is relieved the elastomer dome flips rapidly back to its original form, closing the slits. Flow is cut off, and compensation air can enter—perhaps with some suck-back of any residual product on the valve—because much less pressure difference is needed to open the slits enough for reverse air flow. These slit silicone valves work well, but the silicone elastomer is expensive, and neither recyclable nor degradable.
Our aim herein is to provide new and useful types of valved dispensing closure, and corresponding dispensers, especially with a view to providing a mechanism that requires neither special elastomer materials nor auxiliary springs and the like.